C. L. Boulenger 
135 
part of the work was however carried out in the new Agricultural 
Zoology Laboratory in the University of Birmingham. Nemaiodivus 
filicollis has generally been considered to be a somewhat uncommon 
parasite in Europe, but both in Kent and in the Birmingham district 
this form proved extremely abundant at all seasons and was found in 
a large percentage of lambs and yearlings suffering from gastro-intestinal 
troubles, as well as in a number of apparently healthy animals. 
The worms usually occur in the duodenum but in the case of heavy 
infection are also found in other parts of the small intestine; they 
have been recorded from the fourth stomach as well 1 , I have however 
never come across them in this position. 
Whilst in the majority of cases the parasite occurs in relatively 
small numbers, I have occasionally observed thousands in the duodenum 
alone, the contents of the latter seeming nothing else than a writhing 
mass of worms. Lambs thus heavily infected always exhibited symp¬ 
toms of helminthiasis, to what extent these were due to the presence of 
Nematodirus filicollis is difficult to say as this worm was never found 
by itself but was always associated with other parasitic worms, both 
in the small intestine and in other parts of the alimentary tract. Among 
the- worms found associated with Nematodirus filicollis in the small 
intestine were the tape-worm, Moniezia expansa, and the following 
Nematodes: Bunostomum trigonocephalum Rud., Ostertagia circumcincta 
Stad., Cooperia oncophora Raill., Trichostrongylus viirinus Looss, and 
Strongyloides papillosus Wedl. 
Historical. 
The worm now under consideration was first described by Rudolphi 
in 1802 under the name of Ascaris filicollis. the type specimens having 
been obtained from sheep in Germany. The same investigator removed 
the species to the genus Strongylus in 1803, and under the name of 
Strongylus filicollis we find descriptions of the parasite in many 
helminthological publications, including those of Schneider (1866), 
Curtice (1890), Railliet (1893), and Stddter (1901). 
Ransom in 1907 took the species as type of a new genus Nematodirus, 
and in his monograph on the Nematodes parasitic in the alimentary 
I desire, also, to express my thanks to the Birmingham Natural History and Philosophical 
Society for assistance, by means of a grant from the Endowment of Research Fund, in 
defraying the cost of the illustrations of this paper. 
1 Cf. Neumann (1905), p. 361. 
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